Process for culturing crabs in recirculating marine aquaculture systems

A process for producing a crab species in a closed, recirculating aquaculture system including respective aqueous medium-containing tanks for successive life-cycle stages, including broodstock conditioning, spawning, egg incubation, larval rearing, nursery processing and crab grow-out, wherein photoperiod, water temperature, water chemistry and diet are monitored and controlled to provide regulated process conditions in the aqueous medium tanks including the with the following PROCESS CONDITIONS correlative to LIFE-CYCLE STAGE:

• LIFE CYCLE PROCESS STAGE CONDITIONS Broodstock Salinity:
• 15 ppt-35 ppt conditioning Temperature:
• 15-25° C. Dissolved O2 80% to 100% saturation (DO):
• ORP 96-498 mV Population 4-7 crabs/meter of tank bottom Density:
• surface area Photoperiod simulated natural photoperiod and and thermal Thermal regimes simulating natural Regimes environmental conditions Diet:
• Crabs are fed 1-3 times daily with 2% per kg body weight, per day, of feed including protein and marine lipids Spawning/ Salinity:
• 20-35 ppt egg release Temperature:
• 15-25° C. Dissolved O2 80%-100% saturation (DO):
• Population 1 female/tank density:
• Photoperiod increasing days of 12-15 hours of light regime:
• and −2 dark with transitions between light/dark periods of 45 minutes to 1 hour and 15 minutes;
• conditions culminate in photoperiod simulating natural spawning conditions of April-May. Egg Salinity:
• 26-33 ppt Incubation Temperature:
• 18-25° C. Dissolved O2 80% to 100% saturation (DO):
• Photoperiod no photoperiod requirement regime:
• Larval crab Salinity:
• 26-33 ppt rearing Temperature:
• 18-25° C. Dissolved O2 80% to 100% saturation (DO):
• Population 30-175 larvae/liter Density:
• Photoperiod simulated natural regime regime:
• Diet and enriched rotifers followed Green by enriched artemia Water Environment:
• Nursery Salinity:
• 12-30 ppt Temperature:
• 15-28° C. Dissolved O2 80% to 100% saturation (optimal 100%) (DO):
• Population 4-10 post-larvae/liter, estimated maximum density density of 6000 individuals per cubic meter volume Photoperiod light exposure simulative of a natural wild regime:
• environment. Diet:
• early stage of Artemia through adult stages of Artemia Grow-out Salinity:
• 20-30 ppt Temperature:
• 10-30° C. Dissolved O2 80% to 100% saturation (DO):
• Population 400-800 juveniles per 200 liter tank density:
• Water about 0.5 to about 5 environment exchange:
• volumes/day Photoperiod 15-17 hours of light per day regime:
• Feeding:
• 1-3 times/day of pelleted commercial diet, with crab fed a percentage of their body weight with the percentage of feed decreases as crabs increase in size pH:
• 7.4-7.8

A process of producing a crab species in a recirculating aquaculture system comprising:

• (i) providing respective aqueous medium-containing tanks for successive life-cycle stages of the crab species including broodstock conditioning, spawning, egg incubation, larval rearing, nursery processing, and crab grow-out;
• and
• (ii) providing filtration means coupled in closed loop aqueous medium recirculation relationship with the respective tanks, so that aqueous medium from a tank is filtered for purification thereof and returned to the tank, wherein growth conditions are maintained in each of the respective tanks by the steps of:
• (a) administering nutritive material to each of the respective tanks containing crab or crab precursor feeding species;
• (b) maintaining salinity, dissolved oxygen, pH, temperature and photoexposure within predetermined ranges in each of the respective tanks;
• (c) utilizing a hyposaline aqueous medium as the aqueous medium in the grow-out tank;
• and
• (d) administering, as needed, gonadotropin-releasing hormone (GNRH) or GNRH agonist (GnRHa) to the crab species in a sustained release form prior to spawning of the crab in the spawning tank.